how I add a braided loop to a fly line. This is a Scientific Anglers Sonar GT line. This is built on a 65# core and does not have built-in loops. You will have to add the loops and adhere them to the line.
I use Nano Silk 100d GSP thread to make a knot. You can use a whip finisher or a loop of line to finish the knot. Do this twice, then add a small dab of CA+ glue on each knot. Then clean it up, cover with heat shrink tubing. Then cover it with a thin layer of flexible glue like Softex or Aquaseal UV+
Have landed marlin with this setup. Enjoy!